Multi-level modulation provides lower error resistance than binary modulation (two level modulation), therefore it is common to apply error correction codes to multi-level modulations over noisy channels. Due to the overheads allocated to error correction and other considerations, it is uncommon to apply one to one conversion of multi-level modulation to binary modulation. However, this is not necessarily the case in HDBaseT® standard (version 1.0, version 2.0, and future HDBaseT standards).
HDBaseT 1.0 uses an asymmetric method, sending video, audio, Ethernet and controls from source to sink, and back channel from sink to source. The asymmetric nature of HDBaseT is based on an innovative DSP engine, Application Front End architecture, and a special line coding scheme that provides a better transfer quality to selective data types (such as audio, controls, and Ethernet).
HDBaseT uses 16-level Pulse Amplitude Modulation (PAM16) and subsets of the PAM16, where digital data is represented as a coding scheme using different voltage levels at high rates. This enables HDBaseT to transmit one or more high definition video and audio streams over a single 100 m category 5 or category 6 cable.